Octopuses Taste Danger with Suction Cups
Marine Cephalopods Detect Food Quality via Microbial Signals
Like humans using touch to judge fruit ripeness, octopuses rely on their specialized suction cups to discern food quality. New research reveals these remarkable creatures can “taste” chemicals released by microorganisms, guiding their feeding and egg care decisions.
Unlocking Suction Cup Secrets
A collaborative study involving Harvard University and the University of California, San Diego, has identified unique “chemotactile receptors” (CRs) on octopus suction cups. These receptors are sensitive to tiny molecules, allowing octopuses to distinguish between edible prey, healthy eggs, and inert objects like stones.
Microbial Messengers Drive Decisions
The research team observed distinct microbial communities on different surfaces. Live crabs sported minimal microbes, while rotten crabs were teeming with them. Similarly, healthy octopus eggs differed significantly from decaying ones, which were particularly rich in spiral bacteria. This led scientists to hypothesize that these microorganisms play a crucial role in the octopus’s judgment.
Key Chemical Cues Identified
Experiments involving nearly 300 species of isolated marine bacteria confirmed this hypothesis. Specific molecules secreted by these microbes activated the octopus’s CRs. Two standout compounds were “H3C” (harmane-3-carboxylic acid) from crab-associated bacteria and “LUM” (luminechrome) from egg-related bacteria. Both molecules, despite differing chemical properties, triggered a response in the octopus’s sensory system.
“Taste” Signals Trigger Behavior
Further experiments demonstrated that these microbial signals could elicit distinct nerve reactions and autonomous movements in detached octopus arm sections. When researchers applied H3C to artificial crabs, octopuses actively avoided them, mirroring their reaction to truly spoiled prey. Applying LUM to fake eggs also led to immediate rejection by a mother octopus.
This research indicates that microorganisms act as vital “whispers,” influencing octopus behavior by triggering their chemical “haptic” system. These findings suggest octopuses can effectively avoid harmful substances and protect their offspring, demonstrating a remarkable adaptation to their environment.
Broader Implications for Animal Communication
Scientists believe this “cross-border communication” between microbes and animals may be widespread. Similar microbial influences could affect behaviors like fly egg-laying or mate selection in various species, highlighting the intricate relationships within ecosystems. For instance, research published in *Nature Communications* in 2023 detailed how gut bacteria can influence social behavior in mice (Nature Communications, 2023).
“This study shows how microorganisms influence animals’ behavior and evolution through chemical information. Scientists believe that such ‘cross-border communication’ may be common, such as if flies lay eggs or animal mate choices, they may also be affected by microorganisms.”
